In this study we examined the challenges to providers’ and interpreters’ collaboration in bilingual health care. We conducted in-depth interviews and focus groups with 26 medical interpreters (speaking 17 languages) and 32 providers (from four specialties) in the United States to provide an empirically based framework of provider—interpreter trust. Constant comparative analysis was used for data analysis. We identified four dimensions of trust, theoretical constructs that can strengthen or compromise provider—interpreter trust: interpreter competence, shared goals, professional boundaries, and established patterns of collaboration. In this article we describe how these dimensions highlight tensions and challenges that are unique in provider—interpreter relationships. We conclude with practical guidelines that can enhance provider—interpreter trust, and propose future research directions in bilingual health care.